NAME
xcircuit - Draw circuit schematics or almost anything;
make circuit netlists from schematics.
SYNOPSIS
xcircuit [filename[,...]]
DESCRIPTION
The program xcircuit is a generic drawing
program tailored especially for making publication-quality
renderings of circuit diagrams (hence the name). The output is pure
PostScript, and the graphical interface attempts to maintain as
much consistency as possible between the X11 window rendering and
the final printer output.
xcircuit is mouse, menu, and keyboard-driven, with the
emphasis on single-character keyboard macros.
OPTIONS
- filename[,...]
- Begin running xcircuit by loading in the PostScript file
filename. If filename does not have a .ps extension, xcircuit will
attempt to look for both the filename as entered and, upon failure,
with the .ps extension. The file must be in xcircuit format.
filename may also be a comma-separated list of
files.
BASIC ELEMENTS
There are five drawing elements. These are
as follows:
- a)
- polygon (multiple lines which may or may not be closed and
filled)
- b)
- arc (ellipse segment which may be closed and/or filled as
above)
- c)
- label (any text)
- d)
- curve (based on the PostScript "curveto" algorithm)
- e)
- object instance (see below)
There are two composite elements, which are:
- f)
- path (a connected series of polygons, arcs, and curves)
- g)
- object (something containing polygons, arcs, labels, curves,
paths, and instances of other objects)
MOUSE BUTTONS
The mouse button system, the object library,
and the paged buffer system are loosely based on the Caltech
circuit-simulation program "log" (either "analog" or "diglog").
The general idea is to make the most commonly-used functions the
easiest to perform, and (to the extent possible) to scale
(inversely) the complexity of performing a function with the
frequency of that task. Because this program is tailored to circuit
drawing, the most common functions are drawing lines and moving
object instances. The next most common function is selection of
elements singly or in groups.
Mouse button 1 can be tapped to start a connected chain of
lines, the most common drawing function. In addition, button 1 has
a function called "grab", which occurs after the button has been
continually pressed for a short length of time (about 1/5 second).
As the name implies, "grab" grabs hold of an element which can then
be moved around the screen.
Button 2 can be used to select an item if tapped, and if pressed
and held down, a box will be drawn and everything inside that box
selected when the button is released. In all other cases, button 2
will complete a command. For users who have only two mouse buttons
and do not emulate the middle mouse button with the combination of
buttons 1 and 3, use the combination of the Shift key and mouse
button 1 to emulate mouse button 2.
Button 3 will normally abort a command. During editing of an
arc, spline, or polygon, button 3 will revert back to the previous
form, or abort if there is no remaining edit history.
All other commands are available from the pulldown menus and/or
from the keyboard using single-key macros (with easy-to-remember
mnemonics). Keyboard commands are quicker, since they act on the
present cursor position, whereas menu commands require an extra
step.
BUILT-IN LIBRARY
The library is intended to provide a
convenient way to store and retrieve elements of a picture which
will be used more than once. For the application of circuit
drawing, a built-in library provides basic objects such as
transistors, amplifiers, resistors, capacitors, arrows, circles,
power and ground symbols, and the like. This file is a composite of
several library files (such as "builtins.lps", "analog.lps", and
"digital.lps") which are called by the startup script
("startup.script") The program first looks for the startup script
in the current directory, and then searches in the directory given
by the environment variable "XCIRCUIT_LIB_DIR", and finally, in the
hard-coded global directory ("/usr/lib") if it could not find it
elsewhere. Thus each user can add to or modify the file of builtins
to reflect personal taste. Since the PostScript output contains all
object definitions, these changes to the built-in functions are
inherently transferrable. Xcircuit will automatically resolve
conflicts between objects having the same name but different
contents.
The library is accesible from the pull-down menu or with the "l"
keyboard macro. When inside the library, clicking the first mouse
button on an object "grabs" that object and returns the graphics
state immediately to the page being edited, so that the object will
be placed when the mouse button is released.
ZOOMING
Xcircuit has unconstrained zooming and snap-to
positioning. Objects scale completely: line widths and text sizes
will increase/decrease proportionally with the zoom, as well as
dot/dash spacing and all other features. Xcircuit does have a
minimum integer grid in coordinate space, which translates to 0.005
inches at an output scale of 1. The maximum zoom scale gives a
screen size translating to about 100 by 100 inches at an output
scale of 1. The effective scale can be varied by changing the
output scale (reached from the "File/Write" menu selection) in
order to fit a drawing to a page or to get a grid matched to a
specific dimension. A separate scale parameter changes the scale of
the reported position relative to the output scale (as it will
appear on a printed page).
SNAP-TO GRID
The snap-to grid is an all-important feature
for circuit drawing, wherein it is critical that elements line up
properly with one another. In xcircuit, there is no way to
get off the snap-to grid except by turning the snap function off
and physically pushing elements off the grid. Generally, it is most
convenient to leave the snap functon on and use key macros "+" and
"-" to double/halve it as necessary. In any case, objects can
always be returned to the snap grid with the "snap" function (key
macro "S").
SELECTION MECHANISM
Objects are selected using a variety of
search methods. The select box (formed by holding down mouse button
2 and dragging the pointer) uses the simplest method, searching for
curve/polygon segment endpoints, arc centers, and label and object
bounding boxes falling within the select box frame. General object
selection is more complicated. Polygons, Arcs, and Curves are
selected by their outer edges, not the interiors. Currently this is
also true for filled instances of those types. A line is selected
if the pointer is in a region describing a box around it, which is
adusted according to the scale (zoom factor). Every object has an
associated bounding box, which is rectangular but may be rotated
with respect to the top level window. An object instance is
selected if the pointer falls within its bounding box. Each label
also has a bounding box carefully calculated from the width of the
text string.
Often the selection mechanism will find multiple elements in
range of the pointer. In this case, each object in turn will be
presented, colored in blue (or the specified "querycolor" in the
defaults file), and the user has the option of accepting the
highlighted element for selection using the mouse button 1, or
rejecting it with mouse button 3. When all the elements under
consideration have been accepted or rejected, the program proceeds
to execute whatever function was in progress. This selection method
takes a little while to get used to, but is sensible and seems to
work well.
COLOR
Color in xcircuit is implemented with the idea of
"color inheritance". Every page has a "default color" of black. All
elements which have color value "Inherit" will inherit the default
color, black. If an object instance is painted blue (for instance),
all components in that object which have color value "Inherit" will
inherit its color, blue. The reason for this is that it allows
different object instances to be painted different colors (such as
if one part of a circuit is highlighted for emphasis), while making
it possible for object instances to be multicolored, if necessary.
Changing the color of an object instance will have no observable
effect on the drawing if none of the components of the object
inherit that color. An object may have both normally colored
components and components which inherit their color, in which case
only those components with the "Inherit" value will change color
when the color of the object instance is changed.
SCHEMATIC CAPTURE
XCircuit implements a sophisticated
schematic capture. Unlike virtually all schematic capture software
currently available, xcircuit allows the designer to draw the
circuit in a "natural" way, making use both of schematic
hierarchies and simple hierarchies created simply by grouping
elements together. If the chosen netlist format is hierarchical
(like SPICE), both hierarchical forms will be retained in the
output. For element grouping, input/output ports connecting into to
the group will be determined automatically, from context. A
schematic capture tutorial is available from the xcircuit
website,
http://xcircuit.ece.jhu.edu/tutorial/tutorial2.html.
Netlist types currently available are "SPICE", "sim", and "PCB".
KEYBOARD COMMANDS
Basic keyboard commands:
- Z
- Zoom in by a factor of 3/2. If this key is pressed while a
selection box is active (created with the middle mouse button),
then acts like Zoom Box function.
- z
- Zoom out by a factor of 3/2.
- p
- Pan the screen so that the point under the mouse is brought to
the center of the program window. This function can also be
conveniently performed by clicking on the scrollbars. The
scrollbars cannot be moved continuously due to the slow time for
screen refresh.
- cursors
- The arrow keys perform a pan of one-half window size in the
direction of the arrow pressed.
- l
- Go to the Library of built-in objects. From the library, use
mouse button1 to grab an object and bring it back to the edit
screen, or button3 to return without selecting an object instance.
While in the library screen, the zoom and pan functions can be used
to move around.
- >
- Push into an on-screen object in order to edit that object
- <
- Return from editing an object. Object pushes and pops can be
stacked indefinitely.
- space
- Refresh the screen.
- digits 0-9
- Switch to one of the first ten editing pages. Pages greater
than 10 can be reached from the "Window/Goto Page" menu selection.
- + and -
- Change snap-to grid spacing by a factor of two up or down.
- | : and _
- (Bar, colon, and underline) Change style on the currently
selected object to dashed, dotted, and solid, respectively.
- h or ?
- Print a help page summary of commands
Commands to create elements:
- a
- Arc. Center is fixed at the initial position of the cursor. The
mouse position changes the radius of the circle. In snap-to mode
the arc boundry will pass through the snap point closest to the
cursor. Mouse button 1 cycles from controlling the radius to
controlling the starting point, the ending point, and separately
controlling the minor axis to create ellipse. Mouse button 2
completes the arc.
- b
- Box. This is a convenience function for generating rectangular
closed polygons. Creates a rectangle with one corner fixed at the
position of the cursor. Subsequent movement of the cursor defines
the point diametrically opposed. Mouse buttons 1 or 2 complete the
box.
- s
- Spline curve. The first endpoint is defined by the initial
cursor position. Mouse position adjusts the other endpoint of the
curve. Mouse button 1 cycles from controlling position of the
endpoint to controlling positions of the curve control points and
the curve starting point. Mouse button 2 completes the curve.
- t
- Text. Text starts out justified according to the styles chosen
in the pull-down menu. Text can be rejustified using the menu or by
typing the numbers on the keypad (shift-keypad-1 through
shift-keypad-9). The position of the keys on the keypad
matches the justification. Subscripts, superscripts, font changes,
text size changes, underlining, and overlining are all available
from the pull-down menu. Text edit mode recognizes Home and
End keys to move to the beginning and end of the string,
respectively. If the X11 environment maps control key sequences to
character encodings (such as ISO-Latin1), these may be used to
insert non-ASCII text. Another method of inserting non-ASCII
characters is the use of the backslash character, which duplicates
the action of the Text/Insert/Character menu button.
- M, m
- Make object. Takes all the elements currently selected and
compiles them into an object. The object is then placed in the user
library. The elements just selected are deleted from the screen and
replaced by the new object. The center point of the resulting
object is chosen as the closest snap-to point to the center of the
object's bounding box; if another center is desired, then the
object can be edited using the ">" command and its contents
moved with respect to its origin. Note: Objects cannot have
the same name as PostScript commands or have the same name as any
other object in memory. If such a name is found, an underscore
("_") will be prepended to the name as many times as is necessary
to differentiate it from all other known objects. The name also
cannot contain special PostScript characters such as slash; any
such characters found will be replaced with underscores.
Major editing commands:
- d
- Delete. Select the nearest element or elements and delete
it/them.
- u
- Undelete. Xcircuit saves up to 10 delete events to be
recovered. Delete events are stored in order of occurrence, and the
most recent delete event is the first to be recovered. When
multiple elements are deleted at the same time, all of them are
stored as one delete event, and restored together.
- x
- Deselect. Elements which have been selected can be deselected
on a per-item basis. In order not to be too confusing, deselect
does not query if multiple items are found under the cursor; it
just deselects them all.
- c
- Copy. Make a copy of the object(s) nearest the cursor. Object
is automatically grabbed for moving to a new position. The next
button1 or button2 press will place the element. Button2 will end
the copy, and button1 will continue the copy function.
- e
- Edit. The action of Edit is dependent on the type of element
selected. These are detailed below:
- Label
- Returns to text editing mode, starting with the cursor at the
end of the string. Mode is like regular text entry except that
Button 3 returns text to its original string.
- Polygon
- Grabs one point of a polygon for repositioning. Button 1 cycles
between points, button 2 accepts the new polygon, and button 3
returns to the previous state, unless there is no remaining edit
history, in which case it aborts the command. Key macros available
during polygon edit are:
"x"---Breaks the polygon at the given point.
"e"---Moves edit position to the next point.
"i" or "Insert"---Inserts a new point at the position.
"d" or "Delete"---Deletes the current edit point.
There are four modes for polygon editing; see the "Polygon
Edit" section below for details.
- Arc
- Allows resizing of the radius. Mouse button 1 or the "e" key
will cycle between control of the radius, the endpoint angles, and
the ellipse minor axis. Mouse button 2 accepts the new arc. Button
3 returns to the previous editing state, unless there is no
remaining edit history, in which case it aborts the command.
- Curve
- Allows repositioning of one end of the curve. Originally, the
starting angle of the curve is kept fixed. Mouse button 1 or the
"e" key cycles between the four control points of the curve,
allowing control over the angle of the curve at its endpoint and
the shape of the curve. Mouse button 2 accepts the new curve.
Button 3 reverts back to the previous edit state unless there is no
remaining edit history, in which case it terminates the command.
- Object instance
- Object instances have no properties to change except scale, and
do not respond to the "edit" command. Scale can be changed by
selecting "Options/Other/Object Size" from the menu.
Minor editing commands:
- R
- Rotate the selected element(s) or element under the cursor
counterclockwise in 15 degree intervals.
- r
- Rotate the selected element(s) or element under the cursor
clockwise in 15 degree intervals.
- O
- Rotate the selected element(s) or element under the cursor
counterclockwise by 5 degree intervals. This is currently the
smallest angle resolution available to xcircuit.
- o
- Rotate the selected element(s) or element under the cursor
clockwise by 5 degree intervals.
- f
- Flip an element around a vertical axis defined by an object's
origin for an object instance, or across an axis defined by the
pointer position for arcs, polygons, and curves.
- F
- Flip an element around a horizontal axis defined similarly to
the "f" command.
- X
- If two elements are selected, their order is exchanged (this is
only relevant if one element occludes another). If one element is
selected, it is raised up one in the stack, and if it is already on
top of the stack, it is shuffled to the bottom.
- S
- Snap the nearest object to the snap-to grid. For curves the
control and endpoints are snapped; for polygons, each point is
snapped; for arcs, the centerpoint is snapped; for labels and
object instances, the designated point of origin is snapped.
- j
- Join polygons together. This only makes sense if it is possible
to make a single continuous (open or closed) polygon from the
selected parts. Otherwise a warning will be posted and the parts
will remain separate.
- A
- Attach an element to a polygon, arc, or curve. The element to
be attached must be the one currently grabbed (either by a "drag",
copy command, or edit command). Until it is released, it will be
forced to align its center (object, arc), endpoint (polygon,
curve), or position (label) with the closest polygon, arc, or
curve. Note that this is a very powerful tool for generating, for
example, lines tangent to a curve, or objects arranged in a circle
or along a line.
Library editing commands:
- D
- Delete. The selected objects will be deleted from the library
unless other library objects or pages contain references to that
object. Note: Unlike deleting object instances with the
"d" command, this command deletes the actual object and
releases all memory associated with that object, so the object
cannot be undeleted.
- C
- Copy. Makes a copy of an object from either library page and
places the new copy in the user library. The new object will be
renamed to avoid naming conflicts.
- M
- Move. If one object has been selected, it is moved to the
position of the cursor. If two objects have been selected, their
positions in the library are exchanged.
- E
- Edit label. Edit the object name whose label is under the
cursor. After editing, the object name will be checked for
conflicts with other object names, and altered if necessary.
- H
- Hide object. If the object is a sub-instance of another object,
but is not meant to be used by itself, it can be "hidden" so that
it will not appear by itself on the library page.
MENU COMMANDS
- Write Postscript (W)
- This command brings up a popup menu with a number of options.
First, it gives the name of the file if one exists, or else it
gives the default name of the buffer (usually Page n,
where n is the number of the buffer). Next, it gives a
preview of the picture scale and output styles, which include
Landscape/Portrait orientation and Encapulated/Unencapsulated (full
page) PostScript modes. The former allows adjustment of the nominal
size of the picture when drawn in PostScript. The default scale is
1.00, which makes the text scale of 1.0 about 14 points on the
PostScript page. The width and height of the resulting picture are
also given, in inches, and any of the three values can be changed.
The values of the other two will be updated accordingly. Pages
which have the same name will be grouped together into a single
file, allowing multiple pages to be stored in the same PostScript
file. However, as Encapsulated PostScript does not make sense for
this kind of file, it is not an option.
The Write File button writes the current page to an
output file. If the page has a name other than the default, the
file will automatically be saved under that name. Otherwise, it is
necessary to change the name of the buffer. If a file of that name
already exists on the disk, the button will read Overwrite
File.
- Read PostScript
- Reads in a file of Xcircuit format. The file name is requested
by a popup prompt, and an extension of ".ps" will be added if
necessary. The file is read into the current page, which is cleared
first if anything is in it. If the file is a multiple-page file,
the current page will be overwritten with the first page from the
file, but other pages will be loaded into empty buffers. Xcircuit
can also read "lgf"-format files from the Chipmunk CAD tools
programs "analog" and "diglog".
- Import PostScript
- Acts like "Read PostScript" except that the page is not reset
first, so graphics are added on top of existing graphics on the
page.
- Clear Page
- Clears the current page of all elements and resets the name.
The contents cannot be recovered.
- Alt Color
- Switches between the two xcircuit color schemes. The color
schemes can be redefined through XDefaults (see below). The default
color schemes are black-on-white and white-on-black. The latter is
less straining to the eyes, but the former matches the black ink on
white paper PostScript output. Any color scheme other than
black-on-white is not recommended for drawings with color, as the
actual output does not match the observed xcircuit screen.
- Grid
- Turns the grid lines on and off.
- Axes
- Turns the axis lines on and off. The axes mark the origin (0,0)
of the page. On the top level (TopObject), the origin has no
particular relevance, since encapsulated output will define its own
boundaries, and full-page (unencapsulated) output will be centered
on the output page, not according to the Xcircuit coordinate
system.
- Grid spacing
- Changes the spacing of the grid lines. Default spacing is 1/6
inch, which is about the width of the letter 'W' in default text
scale.
- Grid type/display
- This is a submenu allowing the coordinates and coordinate grid
to be specified in alternate units. Listing of coordinates in the
top window can be in default fractional inches, decimal inches, or
centimeters. Default spacing of grid lines is either one-quarter
inch or one-half centimeter. Selecting an A:B scale With option
"Drawing Scale" causes all listed coordinates to be
multiplied by the scale. Note: Xcircuit will make an attempt
to keep objects on the snap/grid spacing when switching between
inch and centimeter scales. In order to do this, it will change the
output scale by the ratio of 2.54 to 2.5, thus keeping a closer
correspondence between inches and centimeters. To get true
centimeters on the output page, the output scale (from the
"File/Write Xcircuit PS") can be reset to 1.0 at the expense of
having all objects intended for the inch grid displaced off of the
snap grid.
- Snap-to
- Turns the snap-to grid on and off. When the grid is on,
movement and placement of elements is restricted to points on the
snap-to grid.
- Snap spacing
- Determines the spacing of the points in the snap-to grid.
Default is 1/12 inch, which is half the grid line spacing.
- Linewidth
- Controls the default linewidth against which all linewidths in
the drawing are scaled.
- Polygon Edit
- The options in this submenu control how the position of lines
are affected when a point in a polygon is selected for editing.
"Rhomboid-X" mode moves adjoining points as necessary to
keep all horizontal lines horizontal; "Rhomboid-Y" mode acts
similarly to keep all vertical lines vertical. "Rhomboid-A"
is similar to Manhattan mode but also tracks non-Manhattan lines.
The default mode is "Manhattan Box Edit", which is a
combination of Rhomboid-X and Rhomboid-Y. In "Normal" mode,
only the point being edited can be moved.
- Arc/Box/Curve Border
- The options under this menu determine the border style of arcs,
polygons, and curves. If an element is selected, it will be
modified; otherwise, if no objects are selected, the style chosen
is made default for all subsequent arcs, polygons, and curves.
Elements may be drawn with or without borders (but for obvious
reasons cannot be made both borderless and unfilled, which would be
invisible) The borders may be closed or unclosed. For an arc,
closed means that a chord is drawn connecting the two endpoints, if
the beginning and ending angles do not complete a full circle.
Borders may be solid, dashed, dotted, and of varying width.
- Arc/Box/Curve Fill
- The options under this menu determine the fill style of arcs,
polygons, and curves. Fill style may be solid, empty, or one of 7
stipple patterns varying from light to dark, which are drawn both
in xcircuit and PostScript as stipple patterns. Stipples can be
transparent or opaque. Warning: Transparent stipples are NOT
inherent to PostScript and the hacks necessary to implement them
cause slow rendering on a printer or PostScript previewer. Due to
the device-dependent nature of the routines, patterns will look
abnormally large on PostScript previewers. This transparancy
feature has been added with the expectation that most circuit
schematics will not rely heavily upon halftoning. Complicated color
patterns can be created using transparent colored, stippled
elements on top of solid-color elements. Note: Ordering of
elements is according to order created. A different ordering can be
achieved using the "X" (exchange) command. This method is
not especially easy to work with, and hopefully something better
will be implemented in the future.
- Arc/Box/Curve Color
- See the COLOR section above for a discussion of color
inheritance. This menu shows all the colors available to xcircuit
with the option of adding more colors. Currently the entry style
for colors is by name or by RGB content in the X11 style of #rrggbb
where rr, gg, and bb are hex values ranging from 00 to FF. The only
limit to the number of colors is the X Server's colormap depth. If
the colormap is full, xcircuit attempts to allocate the closest
possible color to the one requested.
- Zoom Box
- This zoom feature requests the user to create a box (using
either mouse button 1 or 2, expanding the box while holding down
the button). When the button is released, the view will zoom to the
area of that box.
- Full View
- This zoom feature calculates the bounding box of the entire
picture and adjusts the scale to make it fit comfortably inside the
program window.
TEXT FEATURES
Xcircuit's ability to handle text is arguably
the most complicated part of the program, and also of the
PostScript output. Careful attention to text justification and
style is the key to a good drawing.
- Text Size
- Alters the size of the labels. The value is a scale, with a
default of 1.0 which translates to 14 points on the PostScript page
if the default page scale of 1 is used. If a label is selected,
only that label is affected. If a label is being edited, scale
changes starting at the edit position. Otherwise, it becomes the
default size for all subsequent labels. Size affects the entire
text string. Text size can be changed anywhere inside of a string.
However, text sizes inside a string are all given relative to the
label size, not as an absolute point size. Sizes of subscripts and
superscripts are given relative to the natural size of the
subscript or superscript (2/3 the size of the text for which it is
a modifier).
- Text Font
- Standard printer fonts Times-Roman, Helvetica, Courier, and
Symbol, are readily available. "User-defined" fonts can also be
added; however, support is currently limited, and requires a font
object (.lps) file and encoding (.xfe) file, examples of which are
found in the fonts subdirectory of the xcircuit library directory.
- Text Style
- Four standard font styles are available, matching the standard
printer font variations: Normal, Italic (or oblique), Bold, and
BoldItalic. PostScript matrix manipulation allows slanted versions
of any font, such as Symbol, for which none is otherwise available.
- Text Insert
- The Insert menu allows insertion of special characters which
are otherwise not (necessarily) allowed from the keyboard. These
include tab-stop, tab-forward, tab-backward, kern, half-space,
quarter-space, and "Character". The latter option brings up a page
showing the 256-character encoding vector for the font, allowing
point-and-click entry of any character in the font. "Kern"
instructions allow characters to be offset vertically or
horizontally relative to the rest of the text.
- Text Encoding
- Two standard font encodings are available by default, Standard
(Adobe) Encoding, and ISO-Latin1 encoding. ISO-Latin2 and
ISO-Latin5 encodings exist in the library directory, but require
the use of the program "ogonkify" (not included) to produce correct
output on a printer.
- Super and Subscripts
- Superscript and subscript are designed to closely match those
in TeX output, though they lack the proper context-dependent
kerning and other fancy features of TeX. A superscript following a
subscript results in a superscripted subscript. To get a
superscript on top of a subscript, use the backspace character (see
below). The Normalscript style is the way to get out of a sub or
superscript and return to the normal size and position. Quick
super/sub/normalscripting is available from the keypad with the
"+" (plus), "-" (minus), and "Enter" keys,
respectively.
- Overline and Underline
- Overlining and underlining styles remain in effect until the
next occurrence of a style or font change. Overlining is lower if
all the characters are lowercase and do not include the "tall"
lowercase characters. Overlining or underlining can be stopped at
any time using the No Line style. Over and Underlining is *always*
preferable to using a line. PostScript will adjust the over or
underline to the text size and extent and actually grab the "_"
character and compute its thickness in order to draw the line.
- Tabbing
- From version 2.3, xcircuit allows embedded tab stops. Tab stops
must be defined before using tab-forward or tab-backward. The "Tab"
keyboard key inserts an embedded tab-forward instruction into a
label. Tab-stop and tab-backward can be inserted using the
Text->Insert menu. A tab-forward instruction moves the cursor to
the first defined tab stop forward of the current position. A
tab-backward instruction moves the cursor to the first defined tab
stop backward of the current position. If no appropriate tab stop
exists, the instruction has no effect.
- Backspace
- The use of the backspace character is deprecated from xcircuit
version 2.3. The effect of an embedded backspace is more reliably
produced using tab-stop and tab-backward.
- Halfspace and Quarterspace
- These options allow fine control over spacing, particularly
useful when writing equations.
- Justification
- Text justification always starts with the default, chosen from
the options in the menu, but may be changed at any time using the
numbers on the keypad. The position of the keys on the keypad
reflect the point of justification: 1, 4, and 7 are
right-justified, 7, 8, and 9 are bottom justified, 5 is centered in
both directions. Since the letters drawn by xcircuit are optimized
for the Helvetica font, correct justification is the main way to
get text to come out on the PostScript page in the desired way,
relative to objects or boxes or whatever.
.XCIRCUITRC FILE
Certain parameters of the xcircuit program
can be initialized from a file called .xcircuitrc, which is
first searched for in the current directory, and then in the user's
home directory as defined by the environment variable $HOME.
Commands are:
- library libname
- Loads a library named libname (with or without .lps
extension) into the set of built-in objects.
- override default library
- Causes the default libraries defined in "builtins.lps"
not to be loaded.
- override default colors
- Causes the default colors not to be loaded; this will
not override the allocation of black and white, however, for
obvious reasons.
- font fontname
- Adds a font named fontname (as recognized by a printer)
to the menu of selectable fonts.
- color colorname
- Adds a color named colorname (standard X11 conventions)
to the menu of selectable colors.
- set type value
- Sets internal xcircuit variables, where type can be one
of:
boxedit
Where value is one of "manhattan", "rhomboid-x",
"rhomboid-y", or "normal". Determines the default way
manhattan-aligned polygon edges are manupulated during edits.
linewidth
Where value is a real number indicating the default width
of lines.
beep
Where value can be on or off, depending on
whether or not you want the machine beeping at you when it gives
critical warnings.
colorscheme
Where value is inverse to swap the two color
schemes and make the second scheme appear as default.
CRASH RECOVERY
XCircuit implements a crash recovery system
by which a copy of the current file is made every 15 minutes (see
Xdefaults, below, for changing this value). XCircuit deletes this
file upon a normal exit. If, however, XCircuit crashes or is
terminated by Control-C or other sudden death, the backup copy will
remain. On startup, XCircuit checks the /tmp directory for any
XCircuit backup files belonging to the user. If one is found,
XCircuit will prompt the user for recovery. Note that the backup is
unique in that it contains a copy of the entire user space at the
time of the crash. Filenames may get overwritten, as the backup
will treat all pages as belonging to the same file.
KEY BINDINGS
As noted above, keys can be bound and unbound
through command-line functions "bind" and "unbind". Default key
bindings are used throughout this manual page. Key names use the
notation of /usr/X11R6/include/keysymdef.h, but with the notation
"XK_" being optional, and including the addition of prefixes
"Shift_", "Control_", "Capslock_", and "Alt_", which may be used in
any combination. Note that "Shift_" is not used for ASCII
characters (e.g., "A" is used instead of "Shift_a") unless used in
combination with other special keys (such as "Control_Shift_A" to
distinguish from "Control_a", should that be desired). "Button1",
"Button2", and "Button3" are also valid names indicating functions
attached to the mouse buttons in normal drawing mode. Valid
functions which may be bound are as follows, with their default
values given:
Function name Function performed Default key binding
---------------------------------------------------------------------
"Page", change page, Number keys 1-9 and 0
"Justify", change text justification, Keypad keys 1-9
"Superscript", set text superscript, Keypad +
"Subscript", set text subscript, Keypad -
"Normalscript", cancel sub/superscript, Keypad Enter
"Nextfont", change to next font, Alt-f
"Boldfont", change to bold font, Alt-b
"Italicfont", change to italic font, Alt-i
"Normalfont", cancel italic/bold, Alt-n
"Underline", generate underline, Alt-u
"Overline", generate overline, Alt-o
"ISO Encoding", change to ISO encoding, Alt-e
"Return", embedded return character, Alt-Enter
"Halfspace", embedded half-space, Alt-h
"Quarterspace", embedded quarter-space, Alt-q
"Special", special character, Alt-c
"Parameter", embedded parameter, Alt-p
"Edit Break", break at point, x
"Edit Delete", delete point, d, Delete
"Edit Insert", insert point, i, Insert
"Edit Next", go to next point, e
"Attach", attach line to object, A
"Next Library", go to next library, l
"Library Directory", library directory, L
"Library Move", arrange library objects, M
"Library Copy", get object in copy mode, c
"Library Edit", edit library name, E
"Library Delete", delete library object, D
"Library Duplicate", duplicate object, C
"Library Hide", hide library object, H
"Page Directory ", page directory, P
"Library Pop", return from library, <
"Help", generate help screen, h, ?
"Redraw", redraw the window, space
"View", fit page to window, v
"Zoom In", zoom in, Z
"Zoom Out", zoom out, z
"Pan", center pan, p
"Double Snap", increase snap space, +
"Halve Snap", decrease snap space, -
"Pan Left", pan left one-half page, Left arrow
"Pan Right", pan right one-half page, Right arrow
"Pan Up", pan up one-half page, Up arrow
"Pan Down", pan down one-half page, Down arrow
"Write", popup output window, W
"Rotate", Rotate, r,R,o,O
"Flip X", Flip horizontal, f
"Flip Y", Flip vertical, F
"Snap", Snap to grid, S
"Pop", Return from object edit, <
"Push", Edit object, >
"Delete", Delete element, d
"Select", Select element, Select
"Box", Create box, b
"Arc", Create arc, a
"Text", Create label, t
"Exchange", Exchange vertical order, X
"Copy", Copy element, c
"Join", Join into path, j
"Unjoin", Split path into elements, J
"Spline", Create spline, s
"Edit", Edit element, e
"Undelete", Undelete last deleted, u
"Select Save", Make object from selected, M,m
"Unselect", Unselect element, x
"Dashed", Set line style to dashed, |
"Dotted", Set line style to dotted, :
"Solid", Set line style to solid, _
"Prompt", Execute from command line, %
"Dot", Place dot at location, .
"Exit",
Exit xcircuit
Ctrl-Alt-q
"Netlist", Generate a netlist,
Alt-q
"Swap",
Swap schematic, symbol,
/
"Pin Label", Create pin label,
T
"Info Label", Create info label,
I
"Connectivity", Show wire connectivity,
Alt-w
"Sim",
Generate sim netlist,
Alt-s
"SPICE",
Generate SPICE netlist,
Alt-S
"PCB",
Generate PCB netlist,
Alt-p
"SPICE Flat" Generate flattened SPICE, Alt-f
------------------------------------------------------------------
2-Button mouse users may find it useful to forego the
Shift-Button1 combination and instead put the following commands in
the startup script:
bind('Escape', 'Cancel')
unbind('Button3', Cancel')
bind('Button3', 'Finish')
This will move the 3rd mouse button bindings to the "Escape"
key, and duplicate the 2nd mouse button bindings onto the 3rd.
X DEFAULTS
The color scheme of xcircuit has a default
setup, but accepts alternate color schemes using the following
keywords which can be put in the X Defaults (.Xdefaults,
.Xresources) file, such as:
!
! Sample X defaults for xcircuit, black-on-white version
!
xcircuit*foreground : Black
xcircuit*background : White
xcircuit*gridcolor : Gray85
xcircuit*snapcolor : Orange
xcircuit*selectcolor : Blue
xcircuit*querycolor : Green
xcircuit*axescolor : NavajoWhite3
xcircuit*offbuttoncolor : Gray30
xcircuit*auxiliarycolor : MediumOrchid1
Two color schemes are supported at a time, ostensibly for those
people who prefer the lessened eye strain of a white-on-black
scheme. The names of the secondary colors are the same as those for
the primary colors, but followed by "2", e.g.,
"xcircuit*foreground2".
One other resource defines the number of minutes between
automatic saves to the temporary file (in case of a crash or
emergency Ctrl-C exit):
xcircuit.timeout
: 15
Xcircuit also recognizes the core resources, such as width and
height:
xcircuit.width
: 600
xcircuit.height
: 500
All xcircuit foreground and background colors are taken from the
Xdefaults foreground and background. To get, for instance,
white-on-black menus and buttons with a black-on-white drawing
area, use the following:
xcircuit*foreground : White
xcircuit*background : DarkSlateGray
xcircuit.foreground : Black
xcircuit.background : White
This will ensure that only the drawing area is black-on-white, but
all other windows will appear in the less eye-straining
white-on-black.
Five different fonts can be specified in the Xdefaults. helpfont is
the style of fonts on the help popup window. filefont is the style
of fonts in the list of files in the file selection popup window.
textfont is the style of font for entering text in the popup dialog
boxes. titlefont is the style of font for the cascade menu titles.
boxes. titlefont is the style of font for the cascade menu titles.
All other fonts take the type font. For example:
xcircuit*font : *times-bold-r-normal--14*
xcircuit*helpfont : *times-medium-r-normal--12*
xcircuit*filefont : *times-medium-r-normal--14*
xcircuit*textfont : *courier-medium-r-normal--14*
xcircuit*titlefont : *times-bold-r-normal--18*
xcircuit*titlefont : *times-bold-r-normal--18*
FILES
The file path used by xcircuit to find library files
is system-dependent (i.e., can be changed at compile time), and can
be overridden in many ways (in .xcircuitrc or by the
XCIRCUIT_LIB_DIR environment variable), but by default is:
- /usr/lib
- xcircps2.pro
- PostScript prolog appended to each file
- startup.script
- This startup script contains commands of the type
library name number which cause the designated
library name to be immediately loaded into library page
number. The startup script is also responsible for loading
fonts, and may also be used to load colors on the color palette,
set other options, and execute commands.
- generic.lps, analog.lps, digital.lps, avlsi.lps,
analoglib2.lps
- Files containing pre-compiled circuit elements. The .lps
extension is unique for xcircuit libraries.
- fonts
- This subdirectory contains font definition files for xcircuit's
vector-drawn fonts. Characters are defined by xcircuit objects and
stored in a .lps library. The encoding scheme and other font
information is stored in a .xfe ("xcircuit font encoding")
file.
- ~/.xcircuitrc or ./xcircuitrc
- Personal xcircuit initializer; commands are outlined above.
Libraries listed in this file will be appended to the builtin
libraries.
ENVIRONMENT VARIABLES
xcircuit understands the
following environment variables:
- TMPDIR
- Directory for temporary (e.g., backup) files (defaults to
"/tmp").
- XCIRCUIT_LIB_DIR
- Directory where xcircuit libraries and startup files can be
found (defaults to "/usr/lib/xcircuit-3.3").
- XAPPLRESDIR
- Directory where the xcircuit application defaults can be found
(defaults to "/usr/lib/xcircuit-3.3/app-defaults")
- HOME
- Directory where xcircuit will look for startup files, after
searching the current directory.
- HOST, HOSTNAME, USER
- Environment variables which xcircuit uses to fill in header
information in the PostScript output (HOST and HOSTNAME are
equivalent).
BUGS
PostScript printers have device-dependent limits on
the number of statements within a "def" definition. If an object
definition has an unusually large number of components, xcircuit
will flag a warning when writing the file. However, there is no way
to ensure that a file will be accepted by a given printer. The best
way to avoid the problem is to make sure that large drawings make
good use of hierarchically nested user-defined objects. Note that
printer errors arising from this problem have not been observed in
practice, and given the typical size of on-board memory on most
modern laser printers, probably never will be.
A list of bugs can be found in the Manifest file in the source
directory.
ONLINE TUTORIAL
Look for the xcircuit online tutorial at
http://xcircuit.ece.jhu.edu/tutorial/tutorial.html
SEE ALSO
xfig(1), another
powerful freeware drawing program worthy of mention (see www.xfig.org). Another schematic capture
package worth noting is "gschem" from the gEDA package (see
www.geda.seul.org).
NOTES
PostScript is a registered trademark of Adobe Systems
Incorporated.
XCircuit Copyright (c) 2002 Tim Edwards. XCircuit is freely
distributed under a generous public license. See the source
distribution for details.
Xw widget set Copyright (c) 1988 by Hewlett-Packard Company and the
Massachusetts Institute of Technology.
AUTHOR
Tim Edwards <tim@bach.ece.jhu.edu>. Thanks
to Tomas Rokicki for the PostScript routine which manufactures a
Symbol-Oblique font. Thanks to Dave Gillespie and John Lazzaro for
the program "analog" on which the graphical interface of xcircuit
is (roughly) based. Thanks to many beta-testers, some of whom were
kind enough to send patches. Most contributors have been named in
the Manifest file in the source distribution.